The invention relates to a method for producing a field-effect transistor of planar structure, with double self-aligned gates on each side of a channel and source and drain electrodes, comprising formation of a first gate on a first substrate of semi-conductor on insulator type, deposition on the first gate of a hard layer designed to act as etching mask to bound the channel and a pad that bounds a space subsequently used to form a gate cavity, flipping and bonding of the assembly on a second substrate and formation of a second gate in the gate cavity, photolithographic steps relating to definition of the gates, source and drain areas and channel areas being performed before bonding.